Liverpool are a good team and they have several options for different positions. Well, maybe not as many as Manchester United, but definitely quite a few. Reina of course is the automatic choice between the posts – especially as Dudek is no longer there. Carragher and Agger are solid Center Backs. The full backs can be a problem, as both are rated somewhat low. This invites the option of substituting at least one of them (Arbeloa) for Skrtel. And as Skrtel is not good at Full Back, you should move Agger to the flank and play Skrtel as a CB.
In attack, there should also not be many considerations. Fernando Torres is arguably the team's best player (and one of the better strikers in the game) and Robbie Keane is better that Kuyt.
The Liverpool midfield is the place to experiment. Remember, the unique Fifa 09 Liverpool formation includes one Defensive Midfielder (Mascherano) and one Attacking Midfielder. Steven Gerrard is the default choice for this position, though another interesting option is present (see further). Riera should be substituted at Left Midfield for Babbel, especially if you want to add firepower. Kuyt is not bad as Right Midfielder, but you should probably free the place for Xabi Alonso or Yossi Benayoun. The latter has good technique, but little strength and will be pushed around by stronger defenders. However, there is also the possibility of playing Steven Gerrard as RM, putting either Benayoun or Robbie Keane as AM (in the latter case Kuyt will fill Keane's striker position). If you decide to attack via the flanks this is definitely a viable option.
Overall, I would recommend this squad:
Reina – Agger, Carragher, Skrtel, Dossena – Mascherano, Xavi Alosno, Babbel, Gerrard – Torres, Keane

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